Electrolytic process.



UNITED STATES PATENT OFFICE.

CHARLES J. REED, OF PHILADELPHIA, PENNSYLVANIA.

ELECTROLYTIC PROCESS.

Specification of Letters Patent. Patefited Mar, 11, 1913, No Drawing. original'application filed May 10, 1911, Serial No. 626,148. Divided and this application filed June 3, 1912. Serial N0. 701,296.

To all whom it may concern Be it known that I, CHARLES J.- ltuno, a citizen of the United States, reslding at Philadelphia, county of Philadelphia, and

State of Pennsylvania, haveinvented certain new and useful Improvements in ElectrolyticProcesses, of which. thefollowing is a specification.

My process relates to the electrolytic dep-' iytic deposition ofzinc under the same conditions, is subject to the difiiculty that the metal is not easily or efiiciently deposited in the presence of free sulfuric acid, and as the percentage of free acid in the solutlon increases, the deposition of the metal with a given current decreases. This difficulty was overcome in the case of zinc by a process described by Carl Hering in U. S. Letters Patent No. 798,790,, granted September 5, 1905.

Iron has the same property as zinc of being unreduced and unaffected in solution as sulfate'by contact with metallic lead. I find that an anode of spongy lead may be used to combine with the (S0,) of the sulfate of this metal to produce insoluble sulfate of lead ,and prevent theliberation of free sulfuric acid in the electrolyte. This enables meto electrolytically deposit the metal from its sulfate solution without the inefliciency due to the presence of free sulfuric acid.

In the operation of my process, I prepare a solution of the sulfate of iron and electrolyze it with a cathode of any suitable conducting substance, such as carbon, copper,

.of a lead accumulator. The sumof the reactionsv which take place may be represent- 'ed by the following chemical equation I Pb+FeSO =Fe+PbSO,. This means that the metallic lead com-' ,bin'es with the so. ,of the iron sulfate and the iron is set free in.the metallic state, there being no other chemical changes in the solution. If this operation were allowed to continue, the spongy lead would eventually all or nearly all be converted into lead sulfate. But in practice I find it'advisable to allow only about. one-third or less of the spongy lead to become sulfated, asis'the general practice in the discharge of an accumulator. When this has occurred I .remove the anode (replacing it with a fresh one) "and place it in a dilute solution of sulfuric acid and pass an electric current through it in the opposite direction, usin it as a cathode until the lead sulfate has a l or nearly all been reduced to metallic spongy lead and the S0 liberated as sulfuric acid. The electrode may then be again used as an anode in the deposition cell and the operation becomes cyclic, the sulfuric acid being a by-product which may be recovered and utilized." 1

I do not limit myself to the use of any particular substance as ,a cathode for receiving the deposit of iron, but prefer a sheet of nickel oraluminum. 4

- By the term anode of spongy lead as herein used, I do not meanythat the entire electrode consists necessarily of spon lead, but only that it contains spongy ead as chemically-active material. It may, for example, be made up of a conducting framework of hard lead, antimonial lead or other suitable material capable of conductingtne electric current and having spongy lead applied to or contained in it, as in the ordinary accumulator plate.

This application is a division of Serial No. 626,148, filed May 10, 1911.

I claim:

' 1. The process of recovering metallic iron from a solutionof its sulfate, which con sists in electrolyzing said solution, using an anode of spongy lead, substantially as herein described.

2. Theprocess of depositing metallic iron from its solution as sulfate,- which consists in electrolyzing' said solution, using an anode of spongy lead, and subsequently regenerating said anode material in a sepascribed.

3. The process of reducing metallic iron from its solution. as sulfate, which consists in 'electrolyzing' said solution, using an anode of spongy lead, and electrolytically rate receptacle, substantially as herein deregenerating said anode. material in a sepa? i 0 rate receptacle, substantially as herein set acid as a by product, substantially as herein forth. 1 described.

.. v 10 4. The process of recovering metallic iron In testimony whereof I affix my signature from a solution of its sulfate, which conin presence of two Witnesses.

- sists in electrolyzing said solution, using CHARLES J. REED.

an anode of spongy lead, electrolytically re- Witnesses: generating said anode material in a sepa- FRANK A. LEAGH,

rate receptacle, and recovering the sulfuric J. M. JACKSON. 

